In some cases, but often not due to poor flexibility, you can also
unblock using iron wire.

Having seen the mess corrosion products make of 22mm CH pipe I can't
imagine installing microbore.


NT


Mine was put in in 1988. Had no corrosion problems as I have always
included an inhibitor. I suspect the blockage is debris from the original
instalation. The pipes are all hidden behind platerboard hence my
reluctance to open up the system or change anything.